Wheel mounting



W. F. HEROLD WHEEL MOUNTING Nov. 8, 1949 5 sheets-sheet 1 Filed March 22, 1944 Nov .8, 19419 Fild March 22, 1944 5 Sheets-Sheet 2 W. F. HEROLD WHEEL MOUNTING Nov. s, 1949 5 SheeiS--Sherl l5 Filed March 22, 1944 Nov. s, 1949 I Wv F HEROLD e 2,487,134

WHEEL MOUNTING Filed March 221 1944 l 5 sheets-sheet 4 gig. 6.

Nov. 8, 1949 w, F. Hr-:RoLD 2,487,134

l WHEEL MOUNTING Filed March 22, 1944 5 Sheets-Sheet 5 Patented Nov. 8, 1949 MOUNTING Walter F. Herold, Easton, Conn., A.assignor.. to The B assi'ck Company, Bridgeport; Conn., a.. corporation of. Connecticut ApplicationfMarchzZZ, 194.4,y Serial No; 527555.71:

14' Claims. 15

This;inventiomrelatesA towheel mountings and, more particularly, to resilient mountings for wheels,- ofland vehicles.. The, invention hastparticularapplication .to -tractors ,of the track-laying type, in which: connectionthe. wheel mounting of the invention .-.isfverygA useful and. advantage-ous as applied .to .bogie wheels .which support. the vehicle. bodyI onv thealower runxof theendless track, .but theinventionds also applicableto lwheels used in roadvehic1es-.anddn-various other. relations.

The.V invention. concerns.` itself, among other things, witnthe problem ofspringing the wheels` of. land. vehicles. thatfmayftravel at. a.. fairly. high rateof speed, There-isneedfor. proper. springing of the. vehicle,.both.from.th.e point of View of carrying.. the. loads.- imposed. on the supporting wheels. and. also from. the point.. of view of. the impacts .or shockswhich; are received.. as a result @ff` obstacles.whichv are@ encountered.- or from. une evenness. on the. surface over which. tha vehicle travels..

The invention has yto do, therefore, rin onephase, with.l a. land.. vehicle equipped withV load. bearing springs. and. alsowith. impact receiving springs. the latter, having apredetermined relation to the former.` in. order. that. certain new. and', improved results-may be achieved..

Onelof theobjects ofthe inventionis to provide. a vehicle in.. which. wheelsl supporting the vehicle.. on. the.. ground: are.. equipped, with. impact receiving springs and in which these springsare coordinatedin ,an improved. manner witlrsprings which are'primarly load .bearingsprings Another. obj ectlis to. provide the improvements just'.mentione.d. in,l a vehicle of the track. laying type Where the. Wheels which, aremountedand operate man improved manner. are bogie wheels over which the endless track travels.

Another object.. is to` provideI an. improved mounting for bogie wheelsoftrack l'ayingvehicles whereby what. may. be. termed road shocksA are much: more effectively taken up and absorbed than has `been the case previously.

To these and other. ends, the invention consists inl the novel' features. and' combinations of parts toV be. hereinafter described and nally pointed out inthe claims.v

In the accompanying drawings:

Fig. 1L is a fragmentary side elevation of a track laying vehicle equipped' with. my improvements, the loadfbearingsprings and their housing being shown in section,the,two.bogie wheelsshown being in. positions whichthey. assume .when the ve.- hicle stands on.a leve1.;surface.;.

Fig, 2' is. aviervc similar toA Fig. 1',.showing the 2. positions .which the parts. assume in encountering., an. obstacle;

Fig, 3 is a sectiononline 3,-3..of.Fig. 1;.

ll'ig.,3A isasectionon lineBA-BA oflignl,l

Fig...4.is an .enlargedlviewof theleft hand bogie.. wheel of Eig.. 1, certain partsbeing brokenaway, showing the position of the spiral spring whenjtv isnot. subjectedto shock. or impact;

Fig.5 isasimilar View, .showing the. same. Wheel.

inanupper positionin its-support due toshockor. impact.. occasioned by. uneven. ground;`

Fig, 6'is. a section on line 61-6. of Fig. .4;

Fig..8` is aview similar. to,v Fig. 'Lshowing the wheel in lan. upper position .in yits support;y and Fig. 9'is a diagrammatic View, showingtheendr. less track .at one. side ofthevehicle.

In the instanceselectedpfor. illustrating: theinvention, the latter is. embodied, ina. track. laying tractor structure and particularly. in thesupports provided. for the, bogie Wheels which. support. the lower runof the-endless. track. For purposes. of illustration lmerely,.the bogiewheels .are shown in association with load carrying. springs of, a cer,- tain kind, which,.through.a certainA pressure arrangement or mechanism, cause thewheelsto be pressed.againstthelower run. of the track; but many. variations. can be; made so far asthese features .are concerned.. In general, the. arrangement'. of oneofthe tracks or beltsonthetractor may be as illustrated inthe diagram, .Eig..9, Where an endless track Ill. is driven from. a. forward sprocket wheel. II and runs at the rear.` of the vehicle over. anidler I2, the trackloop beingsupported. and tensioned by devices I3 and. I4 locatedwithinthe bight of the trackand .arranged in. tandem. formation, each such. device having, a pair. o f.bogie wheel'spressing against the lower run of thetrack.

It may be assumed that. the .Wheelmountingilllustrated. inthe remaining views-of the drawings is vthed'evice I3 billig. 9.0i'. a device havingasimif lar location4 andi function..

In Figs. 1, 2, and3, the body. ofthe tractor. or other vehicleis indicated' at I5.an'd`, the front and. rear bogie wheelsofjt-he Aassembly are. indicated at I6' and] IT.' These Wheels are independently swung. fromgthe body of the vehicle, being. car.'- ried, in thi's particular instance, at. the free ends of arms. of'whichthe other ends are pivloted4 t'o the body toswing in. a vertical. plane extending lengthwiseoff the vehicle. The wheel'y It,v is. car.- ri'eclA by; forwardly extending.. arms I8.,. and the wheel, I1 by rearwardly extending. arms I9.v In the form shown, thearmsl I 8;'and L9. are. pivotally mounted by means of pins 29 and 2l respectively, said pins being lo-cated in proximity to each other and mounted at the lower end of a bracket structure which is applied to the side of the vehicle body and is generally indicated at B. This bracket structure B, as hereinafter described, carries springs and other devices for imposing downward pressure on the bogie wheels I6 and I'I.

The arms I8 and I9 are of duplex arrangement, there being an arm at each side of each wheel, the two arms of each wheel being suitably connected to the ends of the wheel axle, the axle of each wheel being indicated at 22. The bracket member B has a chambered member or housing 23 having an inner wall 24 suitably fastened to the side of the vehicle body, and an outer wall 25. The pins or pivots and 2I extend between and are held in notches at the lower portions of these walls 24 and 25, being held in position in the notches by lower positioning blocks 26 and 21. In Fig. 3A, the pin 20 is shown, and it is seen that arms I8, associated with this pin and pivoting thereon, have end sleeves I8Ev embracing portions of the pin, there being a spacing sleeve 28 interposed between the sleeves. It is, of course, understood that the arms I9 are mounted in a similar manner.

The mechanism whereby downward pressure is exerted upon the bogie wheels may be greatly varied, but, in the case illustrated, it includes hel ical compression springs located within the housing 23 and interposed between the top wall 29 of this housing and a vertically movable follower plate 39, said plate 39 acting on forked pressure members 3| that exert downward pressure upon the arms I9 and I9. The load carrying springs in the case illustrated comprise a rearwardly located pair 32 of concentric helical springs and a forwardly disposed pair 33, these springs pressing downwardly upon the follower plate 30, which has inner and outer trunnions 34. Each trunnion 34 is located adjacent a sidewall of the housing and is engaged in an opening 35 provided in the upper part of a pressure member 3l. One of the pressure members 3l acts against an arm I8 and an arm I9, and the other pressure member acts against another arm I8 and another arm I9. Each member 3| comprises arms 3la branched olf from each other at an obtuse angle, and, at the extremity of each arm Bla, is a rounded part SIb in the nature of a foot, bearing against a pressure plate 35 mounted upon the upper edge portion of the arm I8 or I9, as the case may be. The arrangement is such that the devices 3| are rockably mounted on their intermediate pivots provided by the trunnions 34, so that downward pressure of the springs 32 and 33 on the bogie wheels is continued as a forward wheel and a rearward wheel are displaced relatively to each other in a generally vertical direction.

The bogie wheels I6 and I1 are preferably formed with a rigid body 31 and a solid rubber tread 38, the latter having a relatively wide surface bearing against the track links II)a at their intermediate portions. The links 10a are pivoted together by means of rods or pintles 39, and these pintles usually carry, at their ends, projections l39a which are engaged by the sprocket wheel II (Fig. 9) for the purpose of driving the track or belt. The track links are so arranged relatively to the bogie wheels that the track will not be displaced laterally relatively to the wheel, and for this purpose the links IIJa are usually equipped with guide lugs 40 projecting upwardly alongside the lower part of the wheel in the manner shown in the drawings, although this is only by way of example.

In the improved wheel mounting, each bogie wheel has a resilient mounting relatively to its carrying arm structure or like support so that when the wheel is subjected to sudden shocks or impacts it can have a certain amount of cushioned movement relatively to its support. In the preferred form, the wheel proper is revoluble on a skein having an eccentric mounting with respect to a stationary axle provided for the wheel, and the wheel is cushioned by means of a spring in the form of a pancake spiral, the outer end of the spring being connected to the wheel support and the other end being connected to the skein. The arrangement is such that, when the skein is turned in a direction for raising the wheel relatively to the axle, the spring is energized by a winding action thereof. This mechanism is used for counteracting the effects of road shocks and uneven ground, in the manner hereinafter described.

Referring to Fig. 6 is is apparent that the axle 22 is in the nature of a pin extending between the arms I9 and passing through holes 4I in said arms and fastened in place by means such as nuts 42. For a considerable portion of its length, the axle 22 is embraced by a sleeve 43. This sleeve is surrounded by a skein 44 which is of generally cylindrical shape but is provided with an inner bore 45 that is eccentrically located relatively to the skein. At one end, usually the outer end in reference to the Vehicle, the skein is continued axially beyond the face of the Wheel, as shown at 46, in order to be fastened to a spiral spring 41, the outer end of the spring being fastened to one of the arms I9 by means such as a bracket 48 and a fastening bolt 49. The body 31 of the Wheel comprises a hub portion 59 which embraces the skein 44 and is revolubly mounted thereon by means of suitable bearings. In the case shown, the bearings comprise inner races 5I, tapered rollers 52, and outer races 53. One of the roller bearings is held in place by a shoulder 54 on that end of the skein which is adjacent the spring 41.

The other roller bearing is held in place by a nut 55, threaded on the other end of the skein, and the nut 55 is held in place by a cap 56. Suitable sealing rings may be employed for preventing dust and dirt frorn'obtaining entrance into the roller bearings.

The cap 56 has an eccentric hole and is arranged over a thrust collar 51 interposed between the end of the sleeve 43 and the adjacent supporting arm, and the cap is secured in place by suitable means which it is unnecessary to illustrate in detail. A thrust collar 58, similar to the collar 51, is used at the other end of the axle for spacing the sleeve 43 from the supporting arm at that side of the assembly.

The pancake spiral spring 41 is preferably constructed of steel and the same has a number of turns which, in the normal position `of the wheel shown in Fig. 4, are spaced from each other to an appreciable degree. The innermost turn of the spring embraces the enlarged portion or extension 46 at the lend of the skein. It will be noted that, in the particular form shown, the outer cylindrical surface of portion 4S is concentric with the axle 22 and that the innermost turn of the spring conforms to portion 46 over a considerable part of the circumference of the latter. The extremity of the spring preferably lies against the cylindrical surface of portion 46 and is secured thereto by means which it is unneces.

saryitoiinustrateindenni, as--the sam-e formno partoff'the present-invention; The outer. end of thespring may besecuredlto thebolt 49. or like member inIany suitablemanner as lby.l having an eye 59'L for-med on-the spring and engaging the -bolti49'f The vpart lllfsupporting.the bolt'from the arm is shown as a separate part weldedlto the arm, but, obviously, variation can-be made in this respect;

For holding the skein in 'a' predetermined vangu lar' position; suitable means arefy provided, and,

in this particular instance, radial lug 6i),v pro-- by across' mark' 3, whereas the center of thek skein, in other wordsthe axis about which the wheelrevolves; is indicatedby a cross mark B4. It" being noted' that the direction of travel of the vehicle is toward the right of Fig. 7, as indicated by the'arrow; it is apparent that axis 64 is below and'to a' slight extent rearwardly `of axis 63 with Iespectto the vehicle', In this example, the angle ofdelection of 'axisfrom the vertical plane of axis B-Sis about twentyive degrees. In this position; the Wheel is near the lower limit of its possiblemovementrelatively to the supporting arm i9. In Fig. 8;,the wheelis shown at' the upper limit ofy its possible-lift relatively to the supporting arm, for., in this position, the skein has been` turnedjuntilits axis 64is vertically above axis 63.

In this particular case, the skein, in moving from the position of Fig. 7 t0 that of Fig. 8, has moved through an angle of about one hundred and iiity-iive; degrees. This is the same position shown in- Fig. 5. As the skein is moved through thisangle, the spring is Wound, and the resistance becomes' progressively greater as a result of the building up or the resistance. increased also to an extent by the fact that after a certain amount of angular. movement of the skein, the turns ofV the spring begin tornake contact with each other, this enf-ect commencing at the inner part of'the spring and the effect Ibeing extended outwardly as the skein is turnedfarther. For the reasonjuststated, the spring has a snubbingaction which causes a damping of themovably mounted' Wheellwhenit issubjected to impactv from beneath, the tendency being to slow down and control the movement of the wheel center soasto prevent rebound and chattering.

Itwillbe seen that arms i8 and I9, supporting the bogie wheels, are at small angles to a horizontal plane, in the position of Fig. 1, and that thesprings-3233-, acting onthe pressure devices 3|, exert athrust on the wheels, the direction of which is substantially. vertical. Through this thrust,.thevload of.. the vehicle is resiliently supported; The arms IB' and l9lswing on theirpivotsfwhenthevehicle moves over uneven ground, as-:shown forexample in Fig. 2 where the forward WheeLisraised to a substantial extent by passage overf'aniobstacle, butin this case also, the thrust oithe. loadbearing spring is substantially vertical, thatzis, it .is .exerted in a` downward direction. Thearesilientimountings `for thezwheels, provided This resistance is.

in this particular case@ at.. ther ends;v offthe# supi-f porting: arms,. are.y provided?. for f ai. diierent purf^ pose, namely, absorbing; shocks.: due toi uneven;

ground, andthe thrustexertedabyfthezsprings-47k` of.' the wheel. mountings: is: exerted a.A direction'.

for absorbing roadZ shocks',-` thisdirection: beingz: atl` an.A angleL tofI the'.` thrustf of the1 load. bearing'.

springsandi moreispecica'lly, in.aulateralf.rather!Y than a. verticali direction. The.. arrangementis: such that'the springs 4 1 in'athe normalipo'sitionfoi' thewheelMFig. 1)'1 press them forwardly: oripress: them with a large' forward component".-so.--th"at,A whenN al wheeli encounters` an. obstacle:-` suclify as shown in Fig'. 23 it"give'srr in. airearwarddirection, inother words, iny a direction@ counterl to the.l` movement ofthe-vehicle: Simultaneously,V the@r entire-wheelmounting-maybelifting, as\-\showrr in:Y Fig-z 2 and compressingfth'e'loadbearing:springs: Asl` thee vehicle moves; forwardly and encounters;

stacleshor unevengroun'd isrtl'i'atiablowfisfreceived counter to the direction of travel, and, byfper mitti'ng the wheel'sunder suoli circumstancesto move rearwardly i'ntheir support's'under'the'control ofistrongI springs; suclislfiocks are Iveryrwelh absorbed', and', inthe case-uffa track'laying'vehilcl'e, a bogiewheel,` mountedlinitl'e manner`v dem scribed, will cushion the track..z and willg support-. andi hold it in a manner-which has not been*y possible heretofore:

In the caseofA a'track'layingvehicle; whereethe shock is transmitted to'vtheebogiefwlieel' through the track, it is. advantageousjk to position` theI skein axis I y64 somewhatA rearwardly of" theA axi'sf of the axle, but, in' som'eicases; it maybe' ad vantageous; tov position" the skein axisr directly belowv thecenteroff the axle:

Another advantage'A of the improvedstructure results fromthe@ relatively widerv angle of* move`- ment prov-idedfor the skeinias the wheel is lifted; relative-ly to its supporting arm` orfother r`supper-t; Inv the case illustrated", thisl angle: abouttone hundredv andiftyve'- degrees, and; asfthewheel axis moves-through suchen'angle, itsfmovement can bev damped andlcontrolledi in` a'` very-'effective way. Such a wide angle may-'not be necessary in allf cases, and that mentionedl is' .merely by way of example.

It is understood,` of; course, that; while therfor wardbogie wheell illustrated is carried" by forwardly projecting'arms andfthel rear Wheel" by. trailingV arms, the cushioned or knee action mountings of the two wheelsv aree-arranged and act in the samemanner; Inzthe-caseshown, the bolts 49, to which the endsofitlie springs 4T are secured, in the normal position'l (Fig. 1),.` are located' in the4 same vertical plane asftheA associated axle 2i2. It is, however, obvious that variation maybe made in this respect" and in others.

In the: initial setting of: thev describedi. torsion joint between the Wheel'and its4 axle; alinefinf tersecting the axle center and the wheel". center will form anf angle of aboutv sixty-five; degrees to a horizontal plane, the wheel center. being, therefore, beneath or under the axle center to facilitate rearward movement.y of. the wheel cene ter when the vehicle meetsanV obstacle. This specific angle is notof importance, but, in.order to secure` the best results. theL angle from the horizontal should be in excess of thirty-live de.- grees inl order` that substantial rearward movement ofthe` skein relatively to itssupport may be permitted.

By the present invention, theA problem" of proper springing of the vehcle wheels is much easier of solution than heretofore, and this is especially true in the case of track laying vehicles although the invention is not limited in its application to vehicles of that nature. The cushioned wheel mountings, provided in addition to the load bearing springs, enable the vehicle to make much better progress over rough ground, the shocks or impacts being absorbed much more effectively than heretofore, and the travel, for that reason, being very much smoother, there also being much less vibration.

Another very important advantage is that, as a result of the present improvements, the wear on the rubber tires of the bogie wheels is very much decreased, and this is a very important factor at the present time because of the scarcity of rubber. In the ordinary tractor vehicle, the bogie wheel tires receive very hard wear and require replacement very frequently, and overcoming this drawback is in itself a notable advance.

The spiral springs used in connection with the torsion joints between the wheel and axle, which include the eccentrically mounted skeins, are very strong and withstand hard use for a long period. Also, the torsion joints which are provided are of sim-ple and sturdy structure, and there are no diiiicult problems in connection with maintaining the resiliently mounted wheels in good running condition. A spring such as herein described forms a very satisfactory external connection between the skein and the wheel support, permitting a controlled rearward movement of the wheel when a road shock is 1,

encountered. A spring of the form described gives a very satisfactory control of the movement which is permitted between the wheel and the supporting arm or other member which supports it, such movement in this case being in a rearward direction, generally speaking, when an obstacle is encountered, and in a forward direction to restore the parts of their initial position. It is primarily the movement to a rearward position which permits the shock to be absorbed so effectively, the load of the vehicle being carried by other springs. The snubbing or damping effect provided by the skein-connected springs is also a matter of distinct advantage.

Nothing herein contained is to be understood as asserting a claim to the particular manner of connecting the spiral spring to the skein or the particular means used for mounting and locating the end cap and bearing adjusting nut at the other end of the axle.

It is understood, of course, that the radial lug 60 or equivalent part carried by the skein, in contacting the cooperating stop member carried by the wheel support, acts to maintain the skein normally in a position in which the wheel center is below the axle center and can move upwardly and rearwardly and then upwardly and forwardly when the vehicle receives a road shock. When this occurs, the stop carried by the skein moves away from the stop carried by the axle support. As the vehicle moves over the obstacle or the like, the spiral spring acts to return the parts to their initial position with the skein stop again in contact with the stop on the axle support.

In referring to a pancake spiral" spring it is intended to indicate that the spring lies in substantially a single plane, as distinct from a volute spring, which is extended in the direction of the axis of the coil.

While I have shown herein only a single embodiment of the invention, it is understood that numerous other embodiments are within the principles of the invention and that various modifications in the organization of parts and in the details can be made within the scope of the claims.

What I claim is:

1. In a vehicle wheel mounting, the combination of a wheel, a wheel support, means for mounting the wheel support from the vehicle body which permits upward movement of the wheel under load, a load carrying spring resisting such movement, and cushioning connecting means between the wheel and the wheel support allowing limited movement of the wheel with respect to the Wheel support in a generally rear- Ward direction under road impact, the wheel center being capable of upward and rearward swing through an arc in excess of 35 and being capable of swinging movement through an arc of more than 100.

2. In a tractor vehicle, the combination of a vehicle body, an endless driven ground engaging track at one side of the body, an axle, a swinging arm carrying said axle from the body, a spring acting on said arm, a skein mounted for turning on the axle on an axis eccentric to the skein, a bogie wheel engaging the lower run of the track and revolubly mounted on the skein, and resilient means normally holding the skein in a predetermined angular relation to the axle connecting the skein exteriorly to the arm, said skein normally having its center below and somewhat rearwardly of the axle center.

3. In a tractor vehicle, the combination of a vehicle body, an endless driven ground-engaging track at one side of the body, an axle, a swinging arm carrying said axle from the body, a spring acting on said arm, a skein mounted for turning on the axle on an axis eccentric to the skein, a bogie wheel engaging the lower run of the track and revolubly mounted on the skein, and resilient means normally holding the skein in a predetermined angular relation to the axle connecting the skein exteriorly to the arm, said skein normally having its center lbelow and somewhat rearwardly of the axle center, and the wheel center being capable of a swinging movement in excess of 100" relatively to the axle.

4. In a wheel mounting, the combination of a vehicle body, an arm pivoted at one end to said body, spring means exerting downward thrust on said arm, an axle carried by said arm, a skein mounted for turning on the axle on an axis eccentric to the skein, a supporting wheel for the body revolubly mounted on the skein, a spiral spring connected at the outer end to the arm and at the inner end to the skein, said skein and spring being arranged so that the wheel center is normally below the axle center and is capable of movement rearwardly and upwardly with reference to the vehicle body when an obstacle is encountered, and a stop member carried by the skein which in the normal position of the wheel engages a cooperating stop carried by the axle support and moves away from said cooperating stop when an obstacle is encountered.

5. The combination of a vehicle body, a wheel support movably carried by said body, an axle carried by said wheel support, a skein mounted for turning on the axle on an axis eccentric to the skein, a supporting wheel for the body revolubly mounted on the skein, a spiral spring connected at the outer end to the wheel support 9 and at theiinnerJend-toithe skein,r-'said skein and spring being arranged so-.that the wheel center :is normally below the axleA center and-is capable :of movement rearwardly andupwardly-with ref.- verence to l.the vehicle body lwhen aniobstacle 1s encountered, and a stop member carried bythe `,skein-which in the normal iposition of-the wheel engages ,-acooperating stopicarried by the axle support and moves away from said cooperating stop when an obstacle is encountered.

6. A device such as set forth in claim 5, in which the cooperating stop is located in proximity to the connection of the spring to the wheel support.

7. The combination of a Vehicle body, a travelling endless ground-engaging track mounted on the vehicle body, a bogie wheel supporting the lower run of said track. an axle for said wheel, a member mounting said axle movably :from said body, a spring controlling movement of said member, a skein member interposed between the bogie wheel and the axle providing for arcuate upward and rearward movement of the wheel center relatively to said mounting member when the adjacent track portion encounters an obstacle. and a spiral spring controlling the lastmentioned movement of the wheel connected at one end to the skein and at the other end to said mounting member.

8. The combination of a vehicle body, a supporting wheel supporting the body in its movement over the ground, and means for mounting the wheel so that under ground impact it moves rearwardly and upwardly, said means including an axle for the wheel, an axle-carrying member movably supported from said body, a load-supporting spring controlling said axle-carrying member, and a spring-pressed skein interposed between the wheel and the axle permitting upward and rearward swing of the wheel center relatively to the axle through an arc of more than 35.

9. In a wheel mounting of the type involving an axle, a sleeve embracing the axle, a skein mounted for turning cn the sleeve on an axis eccentric to the skein, a wheel revolubly mounted on the skein, anti-friction bearings interposed between the skein and the wheel, and a resilient member acting on the skein, the combination of a skein having an end extension with a recess at one end around the axle, a thrust collar in said recess acting against one end of said sleeve, a nut for taking up on the anti-friction bearings located at the side of the wheel opposite said skein extension, an end cap overlying said nut,

and a thrust collar enclosed by said end cap acting against that end of the sleeve which is adjacent said nut.

l0. The combination of a vehicle body, a travelling endless ground-engaging track mounted on said body, a bogie wheel supporting the lower run of said track, and means for mounting said wheel so that under ground impact it moves rearwardly and upwardly, said last-named means including arms pivoted in relation to the vehicle body and having free ends, an axle carried by said free ends, and cushioning means interposed between said axle and the wheel enabling the wheel center to move in an arc with respect to the axle center, said cushioning means including a skein eccentrically mounted on the axle and having an extension at one end beyond the wheel and also including a pancake spiral spring connected at its inner end to said skein extension and at its outer end to one of said arms, .and a stop member :carried by the skein which in the normal z'position of :thewheel engages a cooperating stop'carried by theaxle sup- 'port in vorder to hold the spring at afdeiinite partly wound position, said stop member being free to-move away from said cooperating stop when an obstacle is encountered, the wheel center when the adjacent track portion meets an obstacle .having an Aupward vzand .rearward .swing which may carry through an arc ofmore ,than 35.

l1. The combination of a vehicle body, a wheel support movably connected to said body, a spring acting on said support and sustaining a part of the body weight, an axle carried by said wheel support in fixed relation thereto, a skein mounted for turning on the axle by means of an eccentric skein bore, a supporting wheel for the body revolubly mounted on the skein, a spiral spring connected at the inner end to the skein and at the outer end to a part in iixed relation to the wheel support, and co-acting stop members carried respectively by the skein and wheel support which limit the angular movement of the skein, the wheel center being positioned below the axle center when the vehicle travels over a smooth surface and capable oi movement rearwardly and upwardly with reference to the direction of vehicle travel.

12. A vehicle having a driven endless track, a body carrying the track, a bogie wheel having a spring-pressed carrier pressing it downwardly against the lower run of the track and having an axle fixed in respect to said carrier, and an eccentrcally bored independently sprung skein interposed between the wheel and the axle provid-ing a cushioned mounting which raises and lowers the wheel with respect to its carrier as the skein is turned, the skein when the vehicle travels over a smooth surface having its center below the axle center and the skein being free to swing upwardly and rearwardly when the track portion supported by the wheel encounters an obstacle.

13. The combination of a vehicle body, a wheel support movably connected to said body, a loadcarrying spring acting on said wheel support, an axle in iixed position with respect to said wheel support and carried thereby, a wheel, a springpressed skein supporting said wheel having an eccentric bore by which it is mounted on said axle and adapted to raise and depress the wheel with relation to the wheel support when the skein is turned on the axle, and means limiting the angular movement of the skein, said skein having its center below the axle center when the vehicle moves over a smooth surface and the skein being free to move upwardly and rearwardly through an arc in excess of 35 when the vehicle meets an obstacle.

14. The combination of a vehicle body, a wheel support movably connected to said body, a loadcarrying spring acting on said wheel support, an axle in xed position with respect to said wheel support and carried thereby, a wheel, a spring-pressed skein supporting said wheel having an eccentric bore by which it is mounted on said axle and adapted to raise and depress the wheel with relation to the wheel support when the skein is turned on the axle, and means limiting the angular movement of the skein, said skein having its center below the axle center when the vehicle moves over a smooth surface and the skein being free to move upwardly and rearwardly through an arc in excess of 35 when l1 the vehicle meets an obstacle, said limiting means including stops which are substantially in engagement With each other in the normal travelling position but are separated from each other when an obstacle is encountered.

WALTER F. HEROLD.

REFERENCES CITED The following references are of record in the le of this patent:

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